title: Probing cell traction forces in confined microenvironments.
abstract: Cells migrate in vivo within three-dimensional (3D) extracellular matrices. Cells also migrate through 3D longitudinal channels formed between the connective tissue and the basement membrane of muscle, nerve, and epithelium. Although traction forces have been measured during 2D cell migration, no assay has been developed to probe forces during migration through confined microenvironments. We thus fabricated a novel microfluidic device consisting of deflectable PDMS microposts incorporated within microchannels of varying cross-sectional areas. Using NIH-3T3 fibroblasts and human osteosarcoma (HOS) cells as models, we found that the average traction forces per post decreased upon increasing confinement. Inhibition of myosin-II function by blebbistatin in HOS cells decreased traction forces in unconfined (wide) channels but failed to alter them in confined spaces. Myosin activation by calyculin A also failed to affect traction forces in confining channels but increased them in wide channels. These observations underlie the importance of the physical microenvironment in the regulation of cell migration and cellular traction forces.
authors.affiliation: Johns Hopkins Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA.
authors.forename: Phrabha S
authors.initials: PS
authors.lastname: Raman
authors.forename: Colin D
authors.initials: CD
authors.lastname: Paul
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Stroka
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Konstantopoulos
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000295:instrumentation*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D006576:Heterocyclic Compounds, 4 or More Rings / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D008387:Marine Toxins; D051379:Mice; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D009218:Myosins / Q000037:antagonists & inhibitors / Q000378:metabolism; D041681:NIH 3T3 Cells; D010080:Oxazoles / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004129:Dimethylpolysiloxanes; D006576:Heterocyclic Compounds, 4 or More Rings; D008387:Marine Toxins; D010080:Oxazoles; C472645:blebbistatin; C013830:baysilon; C059041:calyculin A; D009218:Myosins